1. Field of the Invention
The present invention is related to personal computers and more particularly to a method in which integrated device electronics (IDE) devices are detected and configured by a basic input/output system (BIOS).
2. Background Art
In IBM compatible personal computers, data are stored on hard disk devices. A hard disk interface standard for Intel 80286, 80386 and 80486 computers called Enhanced Integrated Device Electronics (Enhanced IDE) was developed that provides high performance at low cost. The IDE standard provides that most of the controller electronics that were previously found on a controller card be located at the hard disk mechanism. Since the IDE interface can be placed on the mother board, because of its relatively simple electronics, a controller card is not needed, and hence an expansion slot is saved for other use.
When a user turns a computer power switch on, or presses a reset button, the computer "boots" itself, a term that is shorthand for pulling itself up by the bootstraps. Booting initiates an automatic start program routine that clears memory, executes diagnostics, loads a computer operating system software program into memory from disk storage and executes other routines that prepare the computer for use.
In IBM compatible personal computers the automatic start program includes a set of programs called basic input/output system (BIOS) that are encoded in read-only memory (ROM). The BIOS facilitates the transfer of data and instructions between a central processing unit (CPU) and peripheral devices such as disk drives. Computer systems are designed to perform functional tests of the BIOS every time the computer is turned on. This is called power on system test (POST).
During POST devices that are connected to the computer are detected and must be setup for operation. Prior BIOS device detection algorithms in setup require that a user enter the setup program and supply required information. The information is then stored in memory. This prior procedure requires a higher level of sophistication on the part of the user and costs more money because a larger memory is needed to store all of the information.
Competition between different brands of computers is vigorous, so a way of differentiating one brand from another can be a significant competitive advantage. Also, read only memory (ROM) by its very nature is expensive, so reducing the amount of code to be permanently stored in ROM can significantly reduce the overall cost of a computer.
It is desired that a user can set all Setup options to `Auto` and have the BIOS do all detection and configuration of IDE devices during POST. This allows for a user to know little or nothing about how their computer operates to become productive using it.
It is desired that a mechanism be provided so that IDE devices do not have to be connected in any physical order to be recognized by BIOS and utilized by DOS, MICROSOFT WINDOWS, or any other Operating System.
It is therefore an object of the invention to provide a basic input/output system (BIOS) power on system test (POST) that does detection and configuration of IDE devices during POST.